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Biomedical subjects

M Tesauro

Publications and source records attributed to M Tesauro.

8 recordsLinked to original sources
PubMed2006

Effect of staurosporine-induced apoptosis on endothelial nitric oxide synthase in transfected COS-7 cells and primary endothelial cells.

Nitric oxide (NO) may block apoptosis by inhibiting caspases via S-nitrosylation of cysteines. Here, we investigated whether effector caspases might cleave and thereby inhibit endothelial nitric oxide synthase (eNOS). Exposure of eNOS-transfected COS-7 cells and bovine aortic endothelial cells to staurosporine resulted in significant loss of 135-kDa eNOS protein and activity, and appearance of a 60-kDa eNOS fragment; effects were inhibited by the general caspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp[OMe]-fluoromethyl ketone (zVAD-fmk). In eNOS-transfected COS-7 cells, staurosporine-induced activation of caspase-3 and poly(ADP-ribose) polymerase (PARP) cleavage coincided with increased eNOS degradation and decreased activity. Loss of eNOS activity was greater than the degree of proteolysis. Incubation of immunoprecipitated eNOS with caspase-3, caspase-6 or caspase-7 resulted in eNOS cleavage. Staurosporine, a general protein kinase inhibitor, also reduced phosphorylation and decreased calmodulin binding, an effect that may explain the reduction in activity. eNOS, therefore, is both an inhibitor of apoptosis and a target of apoptosis-associated proteolysis.

Amino Acid Chloromethyl Ketones↗
PubMed2006

Evaluation of Milan University Dental Students' knowledge of health and hygiene risks related to clinical work.

AIM: Several different subjects in the Degree Course in Dentistry and Prosthodontics, including Hygiene, are of fundamental importance to understand and prevent hygiene/ health risks in the dental field. The aim of this investigation is to evaluate the knowledge acquired by students during the Degree Course in Dentistry. METHODS: A questionnaire was distributed to 121 students of the Degree Course in Dentistry and Prosthodontics at Milan University; the questionnaire, drawn up by the Working Group SItI ''Hygiene in Dentistry'' was structured in 3 parts: personal data; transmission of infectious diseases in dentistry; measures to control and prevent cross-infection. RESULTS: The students were all aware of the health/hygiene risks in dentistry; they knew the principal transmissible infectious diseases (while confusing actual risk of transmission with disease's fears) and the procedures at highest risk of cross-infection for patients and dental professionals; they correctly determined the highest-risk categories of patients and the individual protection devices to be used in dental practice. However, they knew little about their own vaccination status; a low percentage of students answered correctly on which environmental matrices can be contaminated or the more technical questions on disinfection and sterilisation procedures for the instruments employed. CONCLUSIONS: The students' replies show they possess a fair theoretical knowledge of transmission risks; however, some gaps exist above all in the practical application of this knowledge, and it appears clear that these should be addressed in detail, possibly with the help of a specific tutor providing support during normal clinical work in the last year of the course.

Cross Infection↗
PubMed2004

[Dental offices and environment quality].

AIM: The aim of this study was to survey, from a microbiological point of view, dental unit water, air and surface quality in public dental offices and in control environments in Milan. METHODS: We studied tap and dental unit water (from fountain, air-water syringe, turbine), at the beginning and at the end of monday and thursday morning activity; air quality with surface air system (SAS) in dental and control offices; handpieces holder, fountain block, arm of the light, dental trolley, inner and outer walls surfaces quality. RESULTS: Water from the dental unit waterline shows average exceeding the law limits 2-3 fold for total bacteriological counts at 37 degrees and 22 degrees, in all examined points, at the beginning of the working day. There is an improvement in the water contamination at the end of the activity. Pseudomonas aeruginosa is frequently found, total and fecal coliforms are absent, while Legionella pneumophila was found only in one control. Air and surfaces quality is quite good, especially in places with ventilation systems in function. CONCLUSION: Dental unit water is the most critical point among those monitored. Water quality has to be improved with specific projects.

Air Microbiology↗
PubMed2000

Intracellular processing of endothelial nitric oxide synthase isoforms associated with differences in severity of cardiopulmonary diseases: cleavage of proteins with aspartate vs. glutamate at position 298.

An endothelial nitric oxide synthase (eNOS) polymorphism in exon 7 (894 G/T) resulting in glutamate or aspartate, respectively, at position 298 on the protein is correlated with severity of cardiopulmonary diseases. Because glutamate and aspartate are considered to be conservative replacements, the polymorphism was thought to be a marker for a functional locus elsewhere in the gene. We now show in transfected cells, primary human endothelial cells, and human hearts, that eNOS with aspartate, but not glutamate, at position 298 is cleaved, resulting in the generation of 100-kDa and 35-kDa products. Recombinant or native eNOS was examined by immunoblotting either in lysates (COS7) or after partial purification over 2',5'-ADP-Sepharose and calmodulin-Sepharose. Immunoblotting after SDS/PAGE with a carboxyl-terminal antibody showed a single major protein band in the predicted position for eNOS at 135 kDa. An additional band at approximately 100 kDa was present only in the recombinant 298Asp eNOS and in the eNOS synthesized by primary cells and heart tissue with a G/T genotype. Using an eNOS amino-terminal-specific antibody, an immunoreactive band at approximately 35 kDa, corresponding to the residual N-terminal cleavage fragment, was observed in those cells with a T genotype. Thus, eNOS with aspartate but not glutamate at position 298 is cleaved, resulting in the generation of N-terminal 35-kDa and C-terminal 100-kDa fragments. Thus, the eNOS gene with polymorphisms at nucleotide 894 generates protein products with differing susceptibility to cleavage, suggesting that, in contrast to prior predictions, this polymorphism has a functional effect on the eNOS protein.

Animals↗
PubMed2000

Ecotoxicological soil evaluation by FETAX.

The frog embryo teratogenesis assay-Xenopus (FETAX) is a powerful and flexible bioassay that makes use of the embryos of the anuran Xenopus laevis. FETAX satisfies the requirements of low cost, reliability and reproducibility and, thanks to its three endpoints (i.e., mortality, teratogenicity and growth inhibition) can detect the xenobiotics that affect embryonic development. In this paper, we have used FETAX to evaluate samples of soils collected in an oil-contaminated area. Embryos were exposed directly to the soil to be tested. Particular attention was devoted to provide a statistical procedure for analysing mortality and malformation data as well as growth retardation.

Accidents↗
PubMed2000

[Hygiene-sanitary risks associated with dentistry in the city of Milan. Questionnaire-based survey].

BACKGROUND: Aim of this investigation is to identify possible sanitary risks connected with the practice of dentistry and to draw up guidelines which may help all those who work in this field. METHODS: Between April and July 1998, we distributed 231 questionnaires to public and private dental offices in Milan, to evaluate dentists' knowledge of sanitary risks in their practices. One hundred and sixteen of the 231 distributed questionnaires were returned. All the dentists contacted, used protective measures such as gloves, masks, glasses, and high-speed aspirators. RESULTS: Survey responses indicated that the most readily transmittable infectious diseases in dentist's practices are, in order of importance, hepatitis, AIDS, airborne diseases, and herpes. Surgery, endodontics, and the use of sharp instruments most likely lead to transmission of pathogens in both patients and dentists. Dentist's knowledge of out-patient treatment is good whereas their knowledge of the use of disinfectants for dental equipment is poor. CONCLUSIONS: The latter suggests the utility of continuing education in this critical aspect of the practice of dentistry.

Adult↗
PubMedDate not supplied

[Quality of some working places in Milan].

Questionnaires were distributed to the responsibles and to the dependents of structures with high turnover of people, to have informations about numbers and typology of instruments, habits of dependents and type of cleanings. In these structures, microbiologic quality of air and of informatic instruments' surfaces were evaluated and efficacy of treatment with some products of cleaning and sanification was verified. Air microbiological contamination was comparable to that found in other similar researchs. Fecal contamination indicators were not found on instruments' surfaces, both before, and after treatment; in 8 cases (3%) Staphylococcus aureus was isolated and in 6 cases (2%) species of not pathogenous staphylococci were isolated. At the beginning of the working day, mean values of total aerobic bacterial count at 22 degrees and 37 degrees, were low, settled to zero after treatment and increased progressively during the week. Infective risk for workers can be considered insignificant because of low microbiological contamination. Specific sanification products seem not to be necessary, since common products of cleaning have the same efficacy.

Air Microbiology↗